A Russian Su-27 Flanker intercepted a U.S. EP-3 Aries signals reconnaissance aircraft over the Black Sea on Monday, posing a risk to the plane and crew, according to officials with U.S. 6th Fleet.

Although aircraft intercepts happen often, Monday's incident over international waters was deemed unsafe because the multirole Russian Sukhoi fighter conducted "a high-speed pass directly in front of the mission aircraft," 6th Fleet said in a release.

"The intercepting Su-27 made an additional pass, closing with the EP-3 and applying its afterburner while conducting a banking turn away," the release said. "The crew of the EP-3 reported turbulence following the first interaction, and vibrations from the second. The duration of the intercept was approximately 25 minutes."

The EP-3 crew captured video of the event, showing the Su-27 banking right of the aircraft.

While the Russian aircraft was free to exercise in the airspace, U.S. officials said the maneuvers were "irresponsible."

"We expect them to behave within international standards set to ensure safety and to prevent incidents, including the 1972 Agreement for the Prevention of Incidents On and Over the High Seas (INCSEA)," the release said.

In January, an Su-27 flew within five feet of a U.S. Navy EP-3 over the Black Sea, crossing directly into the EP-3's flight path and forcing it to fly through the Russian jet's turbulence wake. Meanwhile, an Su-30 fighter jet buzzed a Navy P-8 Poseidon flying over the Black Sea last November. Its full afterburner also caused "violent turbulence," Fox News reported at the time.

Since Russia's annexation of Crimea in 2014, intercepts have become more common in the region. Russian jets have made multiple passes over U.S. surveillance planes over the Black Sea, as Russian forces build up equipment and new training outposts in Crimea.

Similar instances have occurred in the Baltic, where the U.S. and NATO rotate to conduct the Baltic Air Policing mission over Estonia, Latvia and Lithuania.

U.S. Air Forces Europe (USAFE) in January published videos showing two specific intercepts of Russian aircraft over the Baltic Sea in 2017, one Nov. 23 and the other Dec. 13. In each case, neither of the Russian Su-30 Flanker jets broadcast flight codes required by air traffic control, nor did they file a flight plan.

USAFE classified the scrambles as routine. While there has been increased political tension near Russia's borders, "There [has been] no violation of Baltic countries' territory -- not even the airspace," Gen. Petr Pavel, then-chairman of the NATO Military Committee, told reporters in January. "All we have [seen] in the region is increased military presence, more exercises, more flights of long-range aviation, more use of intelligence. But I wouldn't call it 'aggression.'

"Sometimes, we don't distinguish between airspace violation or a need to call what is known as 'alpha scramble,' " he said, referring to times when pilots sit alert, ready to jump into fighters and escort unidentified or bellicose jets out of sovereign airspace. "Most of these so-called violations are because of a loss of communication or human or technical mistake. ... I would say 90 percent of these so-called violations are technical mistake[s]," such as omitting transponder signals, flight plans or properly communicating with air traffic control.